If you need to make a parenthetical (in-text) citation for a source without an author listed you should use the first word from that source as it is listed on the Works Cited page in parenthesis.
The Works Cited page is where one can find all the references that are used in a written work. All in-text citations should be referenced in the Works Cited page and vice-versa. An example of an in-text citation for a book is (Frank 23). It is usually the author's last name followed by the page number.